O2 Lambda Sensor replacement

BennyD

Sea Urchin Pate
Messages
14,994
Standard roughly 500 cells per sq inch vs sports 200 cells per sq inch. The 200 cell cats allow much more flow but don't have as much surface area of catalyst to clean the exhaust gases - so MOT may be a bit marginal on emissions. It's not the hardest job to add secondary 200 cell cats to the the system as a worst case MOT failure scenario. The Larini 200 cell cats do look to be a long way from the engine which would make keeping them hot a problem and in turn reduce their efficiency.

Try holding the tail pipe after the run to the MOT centre! They run hot.
 

dunnah01

Member
Messages
648
Try holding the tail pipe after the run to the MOT centre! They run hot.
But maybe not the 500-600 deg C that cats like to wallow in. The tailpipe probably only gets to about 150 deg C. I might get my 200 cell emissions checked out before MOT to see what's what
 

Gp79

Member
Messages
1,393
Not had a problem with these come MOT time for 2 years running, still well within the limits.
Only 1 pair of cats and assume 200 cell.
Anything over 50 degree is ‘hot’ for a bare hand.
 

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davidhowson

Junior Member
Messages
474
That’s one side done, it had taken me all afternoon as I just couldn’t get the bolt holes to line up on the manifold end.
Much pushing and shoving and eventually I got three bolts in and then the final one was actually a breeze!
Now for the other side....


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D Walker

Member
Messages
9,827
Confirmed today, I have the same 4 bolt flanges on the cat pipes.....so I think I will be ordering these for fitting at service time in May, luckily they split them today to put my x pipe in so the joints won’t be a problem..
 

jasst

Member
Messages
2,313
Confirmed today, I have the same 4 bolt flanges on the cat pipes.....so I think I will be ordering these for fitting at service time in May, luckily they split them today to put my x pipe in so the joints won’t be a problem..

So you could have had those ones on e-bay the other day after all, went for £799 only one bid!
 

D Walker

Member
Messages
9,827
So you could have had those ones on e-bay the other day after all, went for £799 only one bid!
Pulling my puds, thought they were 2 bolt, never mind, there will be more, I have a 3 week shutdown in Nov, overtime will cover it, but as you say....1 bid.....gutted, should have took photos when I was under it....
 

jasst

Member
Messages
2,313
Pulling my puds, thought they were 2 bolt, never mind, there will be more, I have a 3 week shutdown in Nov, overtime will cover it, but as you say....1 bid.....gutted, should have took photos when I was under it....
If I had a working car I would have been after them, nearly did any way, but sensible head won the day.
 

rockits

Member
Messages
9,167
I'm sure I read somewhere that the original system comprised of 600 cel primary's and 400 cel secondary's, so going to 200cel is a major boost to exhaust flow.
I thought the same. My understanding was the US spec cars had 600 cell primaries and 400 cell secondaries. I've decatted my secondaries and no issues on MOT at all. In fact the emission readings were very very low. Probably down to the fact that there are still 2 wacking great big 600 cell cats on each side!
 

davidhowson

Junior Member
Messages
474
And that’s the second one on, just need to clip the wires up out of the way as the second o2 sensor is much further back than it was.

I couldn’t resist starting her up and omg what an amazing sound!

Those who know my car will know it has straight through pipes on the rear so only the middle box is now oem. It was loud before but this has brought a whole new dimension to it.

Can’t wait to try for real.



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davidhowson

Junior Member
Messages
474
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David



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TimR

Member
Messages
2,656
I was hoping you might picture the condition of collapse of the other cat for comparison....!
 

davidhowson

Junior Member
Messages
474
The other side was not in bad shape. All intact but it may be starting to show signs around the edge that something may give one day, best off and away with it.

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D Walker

Member
Messages
9,827
Excellent, thank you, going to order mine when they do the Xmas discount, got a shutdown in November so the overtime will pay for them and SWMBO won’t notice..;)
 

davidhowson

Junior Member
Messages
474
The final piece in this upgrade / refurb storey is the re-installation of my Formula Dynamics DBW Module.
I sent this away to LA to have the programmes checked. Apparently there was a fault which has now been fixed and returned. I found that with the chip in the off position, the engine wouldn't rev freely over 4k. But with the chip switched on, it would.
Anyway, that coupled with the new Larini's and the new O2 sensors we are now good to go!
It's been quite a 12 months with this car, but it's worth doing and there is an incredible sense of personal satisfaction in being able to say that I did it. (And a HUGE saving at the bank too!)
Q.V. My thread on the Heater Matrix and the Hydro-dipping....

Thanks for the continued encouragement for everyone on here, it really helps.

-David-